Vista3 not responding to midi commands

I’m currently sending midi commands from Propresenter (on an iMac) to Vista3 (pc). I’m doing this over usb using a midiplus 2x2. This works fantastic until it doesn’t. For what ever reason, it just stops working randomly and there’s nothing I can do to get it to work again. Restarting of both machines does nothing. Then after 50 times of trying, it just decides to work again. And then it doesn’t work for a while, and then it works flawlessly for 2 months. I cannot figure this out. There’s no firmware errors and everything is up to date. Any help would be awesome.